OBD1 or 2??

i don't know anything about these computers, im doing and LT1 w/ 700r4 swap this winter

 

For a swap, it's best to use an OBDI. (94-95)
However, some people go with a painless or 93 harness and 93 ECM. So that's also something to consider, depending on what your goals are.

 

well the motor is a 97 and im getting obd2 with it....

 

You can keep the 97 PCM if you want and have someone who can reprogram it for you. (or I can help with that )
Otherwise, I'd recommend a 94-95 PCM. You will also need to swap to a 94-95 knock sensor to use the 94-95 PCM.

 

what is the difference between 1 and 2?

also what is the advantages and disadvantages between the two

 

Well, the OBDII keeps a tighter watch over things. It will set a service engine light if you mess with anything. Of course, any of those codes can be disabled and then it will be OK, but, the programming software for it is more expensive and if you decide later on to do some programming of your own, OBDI would be a better choice because you can do the programming on your own for under $150 invested in the cable and software.

If it's a one time sort of deal (where you just drop in the engine in the other car and won't mess with it afterwards) then the OBDII will be good enough, especially since you already have the PCM.

 

Will the 1994-95 LT1 run on 93 ECM. Is the 94-95 PCM interchangeable with 93 ECM with the 94-95 harness or the opposite.

I understand the 93 LT1 does not have a MAF sensor in the air duct.

 

The 94-95 engine (and 96-97 with a knock sensor swap) will run with the 93 ECM and harness. The ECMs are not interchangeable on the same harness however.

 

Thanks, that's great info.

How about the ECM and harness from the Impala SS LT1. I heard that a guy is running a Camaro LT1 engine with Impala SS harness into a swap project. I guess he must've been using the Impala SS ECM, then.

 

Sorry to bring this back.

madwolf,

Will a 93 LT1 engine, from a Camaro, run on a 1994 LT1 harness and PCM. What will need to be changed for the 93 LT1 engine to run in a 94 harness and PCM.

I found a cheap 93 LT1 engine that needs a rebuild and I am thinking to use it to build a 383 LT1 stroker and save my 94LT1 engine. Will I be okay with the 93LT1 engine in a 1994 harness and PCM.

 

If I were you, I'd look for a newer block. The 93 has some differences from the newer engines, however, you can still use it if you want.

To make a 93 engine work with the 94 harness and PCM, you can swap over your oxygen sensors from the 94 engine and also the whole throttle body assembly with the idle air control valve.
That's it.

 

Thanks for the advise. I will take it. I will look for a 95-96 LT1 engine. Will I need any sensors swap to be able to run the 95-96LT1 engine into a 94 harness and PCM.

Does it make a difference if the 95-96LT1 engine is from an impala (Caprice). Are the PCM's the same 94, 95 and 96.

Thanks again.

 

94 and 95 PCMs are physically identical. You can find these in 94-95 Fleetwoods, Roadmasters, Caprices, Impalas, Camaros, Firebirds and some Corvettes. Service number 16188051. Some 94-95 Corvettes got a service number 16181333 PCM that you can flash with a tune for any of those other cars and it will work the same.

The only thing that differs between these PCMs is the contents of their flash memory. (the "tune" is different for all those cars) So you will need to reflash it for the engine you'll be using. This applies to all year PCMs.

The 96 PCM is OBDII (94-95 are OBDI) and is different from the 94-95. The 97 PCM is different as well, but can be flashed with a 96 tune and used in a 96 car. The 96 can be flashed with a 97 tune and can be used in a 97 car.

The 96 PCM was found in all 96 vehicles (that I listed for 94-95) including LT4 Corvettes and LT4 Camaro SS/Firehawks.

The 97 PCM was only installed on 97 F-bodies.

96 service number: 16214399
97 service number: 16242921

I think the best engine to use is a 95, then a 96-97. I would use an F-body or Y-body (Corvette) block. I think most, if not all, Y-bodies had 4 bolt mains which made them stronger.

For the 95-97 engines, you will need a vented opti harness. That's all you need for the 95.

In addition to that, you will also need to swap to an OBDI knock sensor if you plan to use the 96-97 engine with the OBDI 94-95 PCM.

96-97 engine have an extra pair of o2 sensors, a crank sensor and a different ignition coil. If you use a 94-95 PCM, first two will be ignored, but you will need to modify your harness for it to work with the 96-97 coil, or swap your 94/95 coil on the newer engine. Probably easier to swap than trying to find the right wires and then rewiring the whole thing.

 

That explains it very well.

I want to swap an engine with it's PCM (they will come from 95-96LT1 Caprice cause they are plenty here). I want to save my current engine with it's PCM (94 Camaro), since it is programmed for the cam and build.

So, let's say a 96 caprice PCM and LT1 engine in the 94 Camaro harness. Is it going to be a direct swap. How about the opti harnss. Does that mean the whole engine harness or just the end terminal connection to the opti.

 

The opti harness is a separate piece and connects to the main engine harness. I would recommend using a 94-95 PCM on any 94-97 engine. 94-95 PCMs are easier and cheaper to program, that's the primary reason.

When you look for a new engine, keep in mind that most police/taxi Caprice engines were 4.3 liter "LT1s", real code name L99. Those blocks will not work for you. You will need to find a 5.7L block. (letter P in the VIN number)

Honestly, I'd get the thing off an F-body, just to keep things simple.